波罗的海沿岸地区迁徙隼蜓（Aeshna mixta）的秋季迁徙。

Autumn migration of the migrant hawker (Aeshna mixta) at the Baltic coast.

作者信息

Oelmann Yvonne, Fiedler Diana, Michaelis Rune, Leivits Meelis, Braun Andreas, Gschwind Philipp, Neidhardt Harald, Willigalla Christoph

机构信息

Geoecology, Department of Geosciences, University of Tübingen, 72070, Tübingen, Germany.

Lower Saxon Wadden Sea National Park Authority, 26382, Wilhelmshaven, Germany.

出版信息

Mov Ecol. 2023 Aug 24;11(1):52. doi: 10.1186/s40462-023-00415-z.

DOI:10.1186/s40462-023-00415-z

PMID:37620899

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10464154/

Abstract

BACKGROUND

Migratory insects are important for the provision of ecosystem services both at the origin and destination sites but - apart from some iconic species - the migration routes of many insect species have not been assessed. Coastlines serve as a funnel where migrating animals including insects accumulate. Migratory behaviour and captures of dragonflies in bird traps suggest autumn migration of dragonflies along coastlines while the origin and regularity of this migration remain unclear.

METHODS

Dragonfly species were caught at the bird observatory Kabli at the Baltic coast in Estonia in 2009, 2010 and 2015. For the 2015 data set, we used a stable hydrogen (H) approach to trace the potential natal origin of the migrant hawker (Aeshna mixta).

RESULTS

1079 (2009), 701 (2010) and 88 (2015) A. mixta individuals were caught during the study periods (35, 37 and 11 days in 2009, 2010 and 2015, respectively). The migration period lasted from end of August to end of September. Based on the results from our stable isotope analysis, we identified two populations of A. mixta: One (range of isotope signatures of non-exchangeable H [δH]: -78‰ to -112‰) had a local likely origin while the other (δH: -113‰ to -147‰) migrated from northerly directions even in headwind from the South. The former showed an even sex ratio whereas the actively migrating population was dominated by males.

CONCLUSIONS

Our results suggest a regular southbound autumn migration of A. mixta along the Baltic coast. However, nearly half of the sampled individuals originated from the surroundings suggesting either no, partial or "leap-frog" migration. Contrary to our expectation, A. mixta did not select favourable wind conditions but continued the southbound autumn migration in the flight boundary layer even in case of headwinds. The dominance of males might indicate migration as a result of competition for resources. Further repeated, large-scale studies along the Baltic coast are necessary to pinpoint the migratory pattern and the reason for migration of A. mixta. Such studies should also comprise locations north of the known species range of A. mixta because of the rapid climate-change induced range expansion.

摘要

背景

迁徙昆虫对于在其起源地和目的地提供生态系统服务都很重要，但除了一些标志性物种外，许多昆虫物种的迁徙路线尚未得到评估。海岸线就像一个漏斗，包括昆虫在内的迁徙动物会在那里聚集。蜻蜓的迁徙行为以及在捕鸟器中捕获蜻蜓的情况表明，蜻蜓在秋季沿着海岸线迁徙，但其迁徙的起源和规律仍不清楚。

方法

2009年、2010年和2015年在爱沙尼亚波罗的海沿岸的卡布利鸟类观测站捕获蜻蜓物种。对于2015年的数据集，我们采用稳定氢（H）方法来追踪迁徙的混合赤蜻（Aeshna mixta）的潜在出生地。

结果

在研究期间（2009年、2010年和2015年分别为35天、37天和11天），分别捕获了1079只（2009年）、701只（2010年）和88只（2015年）混合赤蜻个体。迁徙期从8月底持续到9月底。基于我们稳定同位素分析的结果，我们确定了混合赤蜻的两个种群：一个种群（不可交换氢的同位素特征范围[δH]：-78‰至-112‰）可能起源于当地，而另一个种群（δH：-113‰至-147‰）即使在来自南方的逆风情况下也从北方迁徙而来。前者的性别比例均衡，而积极迁徙的种群以雄性为主。

结论

我们的结果表明，混合赤蜻在秋季沿着波罗的海沿岸有规律地向南迁徙。然而，近一半的采样个体来自周边地区，这表明要么没有迁徙、部分迁徙，要么是“跨越式”迁徙。与我们的预期相反，混合赤蜻没有选择有利的风况，即使在逆风情况下，它们也在飞行边界层继续向南秋季迁徙。雄性占主导地位可能表明迁徙是资源竞争的结果。有必要在波罗的海沿岸进一步开展大规模的重复研究，以确定混合赤蜻的迁徙模式和迁徙原因。由于气候变化导致的快速范围扩张，此类研究还应包括混合赤蜻已知物种分布范围以北的地点。